Drier



B. R'. ANDREWS.

DRIER.

APPLICATION FILED APR. 25. IsIII.

1,332,65?. I Patented Mar. 2,1920.

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BERNARD R. ANDREWS, F BRAINTREE, MASSACHUSETTS.

DBIEB.

Specification of Letters Patent.

Patented Mar. 2,1920.

Application filed April 2.5, 1918. Serial No. 230,645

To dll whom t may concern.'

Be it known that I, BERNARD R. ANDREWS, a citizen of the United States, residing at Braintree, county of Norfolk, State of Massachusetts, have invented an Improvement in Driers, of which the following description, in connection with the accompanying drawing, is a specilication,' like characters on the drawing representing like parts.

, type which comprise an elongated chamber This invention relates to driers of that or drying tunnel having means toconvey therethrough the material to be dried and also having means to cause a drying current of air to be passed therethrough either in a direction opposite to that in which the material to be dried passes or in the same direction as said material passes.

Some drying tunnels of this type are p rovided on opposite sides with 'battles which have a staggered relation and the purpose of which is to cause the drying air current to take a serpentine or sinuous course through the tunnel so that it will pass back and forth transversely across the material to be dried a plurality of times in order to eect a more eten drying. When a tunnel of this type is used for drying material in the form of sheets which have a size-and shape corresponding vsubstantially to the cross-sectional area-:of the space between the baiiles of the tunnel, the sheets which are located opposite the batlies constitute continuations. thereof so as to assist in causing the drying air current to have the desired sinuous or serpentine course through the tunnel. If, however, lthe sheets to be dried are of irregular shape or of a size smaller than the cross-sectional area of the space between the bailles on opposite sides of the tunnel, then when any such irregular shaped sheet is situated opposite any baille 'there will exist more or less of a space between the edge of the sheet and the edge of thebalile through which some vor all of the drying current of air'will pass thereby detracting from the action of the bellies in giving tothe drying air current its serpentine or zig-zag course. Under such conditions a considerable portion of the drying current of air will pass through the tunnel alongside of the sheets without taking the zig-zag course which will result in drying the edges of the sheets more rapidly than the central portions thereof.

back across the tunnel thereb It is the object of my present invention to provide improvements in drying tunnels of the above-described type by which any tendency of the drying current of air to pass between the baffles and the sheets of material being dried will be broken up and the drying current of air will be compelled to zig-zag tosecure the most effective drying operation. I accomplish this object by providing means which operates to break up any current of air that tends to pass longitudinally of the tunnel between the baiiles and the material being dried, and to cause said 'air to pass transversely across the tunnel, said means being so constituted that it does not interfere with the movement of the material. In the embodiirrent aof the binvention herein shown such means is in the form of a device projectin a sheet of air transversely across the tunnefrom the edge of each baille or from a point acent the edge thereof. The sheet of air thus pro'ected transversely across the tunnel is of su cient strength to prevent any of the drying air current from passing longitudinally of the tunnel between the baies and the material being dried.

In order to give an understanding of my invention, I have illustrated inthe drawin a selected embodiment thereof which wi l now be described, after 'which the novel features will be pointed out in the appended claims.

In the drawings Figure l is a horizontal section through a tunnel embodying my invention;

Fig. 2 is a section on the line 2 2, Fig. 1;

Figi 3 is an enlarged fragmentary sectional view of one ofthebaiiles';

Fig. 4 is a view similar to Fig. 3 showing a di'erent form of battle;

Fig. 5 is a section on the line 5 5, Fig. 4.

Fig. 6 illustrates a regulatable spray' device. which may be used;

Fig. 7 is,y a sectional view showin the means for conveying the sheets throng the tunnel.

The drying tunnel is indicated at 1 and it is provided at one end with a-door 'or opening 2 through which the material to be dried may be introduced into the tunnel, and at the other end itis provided with a door or opening 3 through which the dried material may be delivered from the tunnel. The door or opening :3 is shown as leading into a chamber or compartment 4 which is in the nature of `an equalizing chamber and 1 n which substantially the same air pressure 1s maintained as exists at the exit end ofthe tunnel. The drying current of air is delivered into the tunnel through an inlet Lopening 6 and is delivered. from the tunnel through an exit passage or opening 7. Any suitable air-forcing means may be used for producing the movement of the air through the tunnel. I have herein shown for this ypurpose afan 5 which is connected to the opening 6 by the `conduit 8. The fan is also connected to the equalizing chamber 4 by a pipe 9 so that the same pressure will be automatically maintained in the chamber 9 as exists at the exit end of the tunnel. The tunnel is provided with suitable regulatable heaters 10 and regulatable spray devices 31 situated at different points by means of which the temperature and humidity of the j air canbe controlled independently at 'any desired point. The tunnel is also provided on each side at suitable intervals with bafiles or partitions 11' which extend inwardly toward the center of the tunnel, the bafies on' one side preferably being arranged in staggered relation relative to those on the other side. The purpose of these baffles is to cause the air current to travel back and forth across the tunnel in a zig-zag manner as it passes from one end to the other,as indicated by the arrows in Fig. 1.

The tunnel above described is similar to that shown in my Patent No. 1,268,535, dated June 4, 1918. When a drying tunnel hav'- ing this construction is used for drying material in sheet form it is customary vto suspend the sheets in the tunnell sol that lthey Will extend transverselyy across the same and then to convey the sheets through the tunnel while in their suspended position, the suspended sheets being suiiiciently separated lfrom each other so that the drying current of air can pass back and forth across the tunnel between the sheets. 4

In Fig. 1 I have shown a plurality of such sheets at12, and in practice they will beconveyed through the tunnel at such a rate of speed that each sheet will be dry by the time a it reaches the discharge opening 3 and passes into the chamber 4. The traveling move- `ment of the sheets may be either continuous tracks`14- may be employed, such, for instance, as a chain or belt device to which the poles 13 are connected.

If the sheets 12 are of irregular shape, as shown in Fig. 2, the result will be that when any sheet is situated opposite a baille a more or less irregular space 15 will exist between the edge of the sheet and the bailie, the size of the space depending upon the size and irregularity of the outline of the sheetI 12. The presence of such spaces 15 allows the drying current of air to pass longitudinally of the tunnel between the edges of the sheets and the baiiies and if these spaces 15 are of considerable size substantially all the drying current of air will pass along each side of the tunnel between the sheets and the bafyiles so that relatively little of the drying air current will have the zig-zag or serpentine course indicated by the arrows in Fig. l. Such conditions would result in an uneven drying of the sheets because the edges of' the sheets would be dried much more rapidly than the central portions thereof. To overcome this difficulty, I have provided a novel means which breaks up any air current that tends to pass directly through the spaces 15 and causes the air current to take the desired zig-zag or serpentine course indicated by the arrows in Fig. 1, but which does not interfere at all with the passage of the sheets.

In the illustrated embodiment of my `invention this means is in the form of a device for projecting a sheet of air transversely across the tunnel from or adjacent the edge of .each balie. One wayof producing this sheet of air is by means of a plurality of jet nozzles which are preferably arranged in a row extending from the top to the bottom of the baiie and are situated-at or adjacent the edge of the baiiie and in a direction to deliver the air jets inwardly toward the center of the tunnel. The row of air jets combined form in effect the desired sheet of air. i

Another way of securing the 'desired sheet of air is by making each bailie with a slit extending from the top to the bottom at its edge and providingv for delivering air under pressure from said slit. In Fig. 3 I have 115 illustrated the baile as having a slit 46 in its edge which communicates with a chamber 17 formed in the baiile, said chamber in turn ecommunicating with a passage 18 extending along the side of the tunnel. Where this 'construction is employed a passage 18 will be provided along each side of the tunnel and all the chambers 17 in the baffles will communicate with the passages. Any suitable means may be employed to deliver ain '125 under pressure to the passages 18. One convenient way is to provide a communication 48 between said passages and to connect said' passages to the conduit 8 by means of a pipe 10. 13o

Where nozzles 16 are used they may be placed directly in the edge of each bailie or may be secured to pipes 49 which extend from the top to the bottom of the tunnel at or near the edge of each baffle. These pipes are seen in Figs. 4 and 5, and in Fig. 4 are communicating with a passage 48 which leads into the -passage 18.

With both of Athese constructions a sheet of air will be delivered transversely across the tunnel at or adjacent the edge of each baiie and the sheets of air which are thus delivered inwardly from each baffle will break up any tendency of the drying current of air to pass longitudinally of the tunvnel past the edges of the baiiles and they will operate to direct the drying current of air from one to the other side of the tunnel, thus causing it to take the sinuous course indicated by the arrows in Fig. 1. Hence, even though the sheets of materiall being dried having an irregular shape and spaces 15 of greater or less size exist between the baffles and the edges of the sheets, yet the drying current of air will be compelled to follow the sinuous course desired rather than to travel longitudinally of the tunnel through the spaces 15.

My improvement, therefore, provides means by which irregular-shaped sheets can be evenly and properly dried in a drying tunnel.

If desired means may be provided for controlling the temperature and humidityA of the air delivered from the nozzles 16 thereby to assist in controlling the temperature and humidity of the air at different points along the tunnel. I claimz' 1. In a drier .of the type comprising a dryin tunnel having provision for passing theret rough both material to be dried and a drying current of air, the combination with said tunnel, of bafiles arranged at opposite sides thereof, and pneumaticmeans to prevent the drying current of air from passing through any space which may` exist between the baffles and the material being dried.

2. In a drier the combination with a drying tunnel, of means to cause. a drying current of air to pass therethrough, means to transfer therethrough material to be dried in the form of sheets extending transversely of the tunnel, baffles on opposite 'sides of the tunnel arranged to cause the drying current of air to take a circuitous route through the tunnel, and means to prevent said current of air from passing through any space which may exist between the edge of the baiies and said material regardless of the width of said space.

3. In a drier of the type comprising a drying tunnel having provision for passing therethrough both material to be dried and a drying current of air, the combination with said tunnel, of baflles arranged at opposite sides thereof, and means associated with some at least of said bafHes to project a sheet of air transversely across the tunnel.

A4. In a drier'of the type comprising a dryin tunnel having provision Jfor passin theret rough both materialto be dried and a drying current of air, the combination with said tunnel, of ba'liles arranged at opposite sides thereof, and means to project a sheet of air from a point adjacent to the edge of each baffle,

5. In a drier the combination with a drying tunnel, of means to cause a drying current of air to pass therethrough, means to transfer therethrough material to be dried in the form of sheets extending transversely of the'tunnel, baffles on opposite sides of the tunnel arranged to cause the drying current of air to take a circuitous route through the tunnel, Vand means associated with the baliles to prevent said current of air from passing through the space between the baiiles and material being dried regardless of the width of said space.

6. In a drier or the type comprising a drying tunnel having provision for passing therethrough both material to be dried and a drying current of air, the combination with said tunnel, of baiiles arranged at opposite sides thereof and each having associated'therewith a plurality of j et nozzles, and means to deliver air under pressure from said nozzles. l

7. In a drier the combination with a drying tunnel of means to cause a drying current of air to be passed therethrough, means to transport therethrough material to be dried in the form of sheets, baiiies at opposite sides of the tunnel arranged to cause the drying current of air to. take a circuitous routetherethrough, and means associated with the baffles and conforming automatically to any irregularity in the shape of the sheets to prevent the drying current of air from passing through any s ace which may exist between the bailles an the sheets in line therewith regardless of the size and shape of said sheets.

Inl testimony whereof, I have signed my name to this specification.

BERNARD, R. ANDREWS. 

